A method for simulating an ocular optical system in accordance with which a scene of external things actually seen by an observer through spectacle lenses placed in front of each of right and left eyes is simulated and an apparatus therefor have been disclosed by the present inventor in Japanese Patent Application No. Heisei 10(1998)-288077.
In the method and the apparatus described above, a scene of external things actually seen by an observer through a lens placed in front of a single eye is simulated. In accordance with the above method and by using the above apparatus, the actual human perception can be taken into consideration and the visual perception including fluctuation, distortion and blur felt in the use of optical spectacle lenses such as progressive addition lenses can be closely simulated.
Since a person observes things with both eyes, the simulation of visual perception with a single eye is not always sufficient for the purpose of expressing and evaluating the visual perception of external thing observed through spectacle glasses. Generally on a progressive addition lens, the area for viewing objects of close distance is placed at a position displaced a little bit nasally for the consideration of convergence. Therefore, the shape of the lenses becomes asymmetric in the horizontal direction to some degree. This, by itself, is not a defect but a great progress of the progressive addition lenses. However, in a monocular rotation-based retinal image, the asymmetry in the horizontal direction is faithfully reproduced and the image has distortion different from that in the actually perceived image.
To remove the distortion of the asymmetry in the horizontal direction and simulate the proper human perception, it is necessary to take the function of binocular vision into the simulation. Thus, defining and calculating distortion and blur arising from the function of binocular vision has been the subject of study. In accordance with specific assumptions and methods found by the present inventor, the visual perception obtained by binocular vision can be approximately simulated using image-processing technology.
The present invention has been made under the above circumstances and has a purpose of providing a method for simulating an ocular optical system which enables simulating visual perception having fluctuation, distortion and blur including the function of binocular vision in the use of spectacle lenses such as progressive addition lenses.